Abstract:Sheep milk fat is rich in short- and medium-chain fatty acids，which can provide a distinctive flavor to cheese，but there is a limited application of sheep milk fat in food cheese processing. In this study，sheep milk fat cheese sauce（SMFCS）and cow milk fat cheese sauce（CMFCS）were prepared by a two-step method to assess the feasibility of sheep milk fat as a substitute for cow milk fat in cheese preparation. The results showed that the content of medium- and short-chain fatty acids in sheep milk fat was higher than that in cow milk fat. Notably，the branched-chain fatty acids，which exert a greater impact on sheep's nastiness，were not detected in sheep milk fat，resulting in a milder taste. The dynamic changes of volatile compounds during the preparation of CMFCS and SMFCS were identified by gas chromatography - mass spectrometry. The results showed that a total of 53 volatile compounds were detected in CMFCS and 42 volatile compounds were detected in SMFCS，with fewer aldehyde and alcohol compounds in SMFCS during preparation. The results of electronic nose indicated that SMFCS had higher content of benzene，inorganic sulfide and long-chain alkane aromatic components as compared with CMFCS and commercially available enzyme-modified cheese. The above results provide a reference for the application of sheep milk fat as a substitute for cow milk fat in cheese.